Digital temperature sensing circuit

ABSTRACT

The digital temperature sensing circuit includes a temperature voltage generator configured to generate a temperature voltage varying with a temperature in response to a first reference voltage, divide a supply voltage in response to a second reference voltage, and generate a high voltage and a low voltage, a code voltage generator configured to divide the second reference voltage based on the high voltage and the low voltage and output divided voltages having different voltage levels, and a mode selector supplied with the temperature voltage and the divided voltages, and configured to output a first code or a second code in response to a mode select signal, wherein the first code and the second code have different numbers of bits.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority under 35 U.S.C. § 119(a) toKorean patent application number 10-2017-0164195, filed on Dec. 1, 2017,the disclosure of which is incorporated herein by reference in itsentirety.

BACKGROUND 1. Field of Invention

Various embodiments of the present disclosure generally relate to adigital temperature sensing circuit, and more particularly, to amulti-mode digital temperature sensing circuit, which can selectivelydrive modes having different resolutions.

2. Description of Related Art

A memory system in which data is stored may include a digitaltemperature sensing circuit because some electrical characteristics ofthe memory system may be sensitive to temperature variations. Thedigital temperature sensing circuit may output detected temperature inthe form of a digital code.

Since the digital temperature sensing circuit converts detectedtemperature into a digital code and then outputs a temperature code, thereliability of the memory system may be increased or decreased dependingon the accuracy of the temperature code. Therefore, there is a need toimprove the reliability of codes outputted from the digital temperaturesensing circuit.

SUMMARY

Various embodiments of the present disclosure are directed to a digitaltemperature sensing circuit. The digital temperature sensing circuit mayoutput temperature codes with a varying resolution depending on aselected mode of operation.

In accordance with an embodiment of the present disclosure, a digitaltemperature sensing circuit may include a temperature voltage generatorconfigured to generate a temperature voltage varying with a temperaturein response to a first reference voltage, divide a supply voltage inresponse to a second reference voltage, and generate a high voltage anda low voltage, a code voltage generator configured to divide the secondreference voltage based on the high voltage and the low voltage andoutput divided voltages having different voltage levels, and a modeselector supplied with the temperature voltage and the divided voltages,and configured to output a first code or a second code in response to amode select signal, wherein the first code and the second code havedifferent numbers of bits.

In accordance with an embodiment of the present disclosure, a digitaltemperature sensing circuit may include a temperature voltage generatorconfigured to generate a temperature voltage varying with a temperature,a high voltage, and a low voltage, a code voltage generator configuredto output divided voltages having various voltage levels based on thehigh voltage and the low voltage, and a mode selector supplied with thetemperature voltage and the divided voltages, and configured to outputfirst codes or second codes having a resolution higher than that of thefirst codes in response to a mode select signal.

These and other features and advantages of the present invention willbecome apparent to those with ordinary skill in the art to which thepresent invention belongs from the following description in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified block diagram schematically illustrating adigital temperature sensing circuit in accordance with an embodiment ofthe present disclosure.

FIG. 2 is a circuit diagram illustrating a temperature voltage generatorof FIG. 1.

FIG. 3 is a simplified block diagram schematically illustrating atrimming circuit of FIG. 2.

FIG. 4 is a circuit diagram illustrating a first analog-to-digitalconverter of FIG. 3.

FIG. 5 is a circuit diagram illustrating a code voltage generator ofFIG. 1.

FIG. 6 is a circuit diagram illustrating a fifth amplifier of FIG. 5.

FIG. 7 is a circuit diagram illustrating a sixth amplifier of FIG. 5.

FIG. 8 is a simplified block diagram schematically illustrating a modeselector of FIG. 1.

FIG. 9 is a circuit diagram illustrating a multi-digital-to-analogconverter of FIG. 8.

FIG. 10 is a circuit diagram illustrating a second analog-to-digitalconverter of FIG. 8.

FIG. 11 is a simplified block diagram for explaining the operation of anadder of FIG. 8.

FIG. 12 is a simplified block diagram illustrating a memory systemincluding a digital temperature sensing circuit in accordance with anembodiment of the present disclosure.

FIG. 13 is a simplified block diagram illustrating an embodiment of amemory system including the digital temperature sensing circuit of FIG.1.

FIG. 14 is a simplified block diagram illustrating an embodiment of amemory system including the digital temperature sensing circuit of FIG.1.

FIG. 15 is a simplified block diagram illustrating an embodiment of amemory system including the digital temperature sensing circuit of FIG.1.

FIG. 16 is a simplified block diagram illustrating an embodiment of amemory system including the digital temperature sensing circuit of FIG.1.

DETAILED DESCRIPTION

Various exemplary embodiments of the invention will now be described indetail together with the accompanying drawings. It is noted, however,that the invention is not limited to the described embodiments but mayalso be embodied in other forms or variations thereof. Rather, theseembodiments are provided so that the present disclosure will be thoroughand complete, and will fully convey the technical spirit of theinvention to those skilled in the art.

It is also noted that in this specification, “connected/coupled” refersto one component not only directly coupling another component but alsoindirectly coupling another component through an intermediate component.Also, in the specification, when an element is referred to as“comprising” or “including” a component, it does not preclude anothercomponent but may further include other components unless the contextclearly indicates otherwise.

In the following description, numerous specific details are set forth inorder to provide a thorough understanding of the present invention. Thepresent invention may be practiced without some or all of these specificdetails. In other instances, well-known process structures and/orprocesses have not been described in detail in order not tounnecessarily obscure the present invention.

It is also noted, that in some instances, as would be apparent to thoseskilled in the relevant art, a feature or element described inconnection with one embodiment may be used singly or in combination withother features or elements of another embodiment, unless otherwisespecifically indicated.

FIG. 1 is a simplified block diagram schematically illustrating adigital temperature sensing circuit according to an embodiment of thepresent disclosure.

Referring to FIG. 1, a digital temperature sensing circuit 1000 mayoutput a temperature code T_CODE by converting detected temperature intoa digital code. For this operation, the digital temperature sensingcircuit 1000 may include a temperature voltage generator 100, a codevoltage generator 200, a mode selector 300, and a first multiplexer 400.

The temperature voltage generator 100 may be operated in response tofirst and second reference voltages Vref1 and Vref2 and a trimming codeTrim<a:0>, and may output a temperature voltage Vtemp varying withtemperature, a high voltage Vtop, and a low voltage Vbot. The first andsecond reference voltages Vref1 and Vref2 may be generated fromdifferent internal voltage sources.

The code voltage generator 200 may be operated in response to the secondreference voltage Vref2, and may output divided voltages Vtap<b:0>having various levels depending on the high voltage Vtop and the lowvoltage Vbot.

The mode selector 300 may be supplied with the temperature voltage Vtempand the divided voltages Vtap<b:0>, and may output either of a firstcode COMP1<c:0> and a second code COMP2<e:0> which have differentnumbers of bits in response to a first or a second mode select signalSMSEL or FMSEL. For example, the mode selector 300 may output the firstcode COMP1<c:0> in a first mode in response to the first mode selectsignal FMSEL, and may output the second code COMP2<e:0> in a second modein response to the second mode select signal SMSEL. For example, thefirst mode may be a fast mode, and the second mode may be a slow mode.

The slow mode may require a high-resolution code. Hence, in the slowmode the digital temperature sensing circuit 1000 may output a codehaving a higher resolution than that in the fast mode. For example, thenumber of bits of the first code COMP1<c:0> may be less than that of thesecond code COMP2<e:0> so that the temperature code T_CODE varying withtemperature may be outputted fast in the fast mode. For example, thefirst code COMP1<c:0> may have 4 bits, and the second code COMP2<e:0>may have 9 bits. That is, since the resolution of the second codeCOMP2<e:0> is higher than that of the first code COMP1<c:0>, the timerequired for outputting the second code COMP2<e:0> is longer than thetime required for outputting the first code COMP1<c:0>.

A fast mode select signal FMSEL may be enabled in the fast mode, and aslow mode select signal SMSEL may be enabled in the slow mode. When thenumber of modes is two, e.g. a fast mode and a slow mode, the fast andthe slow mode select signals FMSEL and SMSEL may be outputted as a 1-bitsignal having ‘0’ or ‘1.’ For example, when the fast mode select signalFMSEL is ‘1’, the slow mode select signal may be ‘0’, whereas when thefast mode select signal FMSEL is the slow mode select signal may be ‘1’.When the digital temperature sensing circuit 1000 is used in a memorysystem, the fast mode select signal FMSEL and the slow mode selectsignal SMSEL may be outputted from a memory controller, and may betransferred to the digital temperature sensing circuit 1000.

Further, in the slow mode, the mode selector 300 may output an endsignal END_S whenever the second code COMP2<e:0> having a preset numberof bits is outputted.

The first multiplexer 400 may output the first code COMP1<c:0> or thesecond code COMP2<e:0> as the temperature code T_CODE in response to thefast mode select signal FMSEL or the slow mode select signal SMSEL.

FIG. 2 is a circuit diagram illustrating an exemplary configuration ofthe temperature voltage generator 100 of FIG. 1.

Referring to FIG. 2, the temperature voltage generator 100 may include afirst amplifier AMP1, a temperature compensation circuit 110, a secondamplifier AMP2, a division circuit 120, a third amplifier AMP3, and atrimming circuit 121.

The first amplifier AMP1 may compare a first reference voltage Vref1with a first feedback voltage Vfb1, and may then output a comparisonresult voltage. For example, the first reference voltage Vref1 may beapplied to a positive terminal (+) of the first amplifier AMP1, and thefirst feedback voltage Vfb1 may be applied to a negative terminal (−) ofthe first amplifier AMP1. For example, when the first reference voltageVref1 is higher than the first feedback voltage Vfb1, the firstamplifier AMP1 may output a high-level voltage. When the first referencevoltage Vref1 is lower than the first feedback voltage Vfb1, the firstamplifier AMP1 may output a low-level voltage.

The temperature compensation circuit 110 may output a sub-voltageVsub_temp inversely proportional to temperature in response to thevoltage outputted from the first amplifier AMP1. Also, the temperaturecompensation circuit 110 may output the first feedback voltage Vfb1 andfeed it back to the first amplifier AMP1. The temperature compensationcircuit 110 will be described in detail below.

The temperature compensation circuit 110 may include a mirror circuit111. The mirror circuit 111 may mirror current, generated at a thirdnode N3, to the fourth node N4. For example, the mirror circuit 111 mayinclude first and second switches S1 and S2 which are coupled in seriesbetween a first node N1 and a second node N2, a first resistor R1 whichis coupled between the second node N2 and the third node N3, and fourthand fifth switches S4 and S5 which are coupled in series between thefirst node N1 and the fourth node N4. The first, second, fourth, andfifth switches S1, S2, S4 and S5 may be implemented as PMOS transistors.Gates of the first and fourth switches S1 and S4 may be coupled incommon to the second node N2, and gates of the second and fifth switchesS2 and S5 may be coupled in common to the third node N3. Therefore, themirror circuit 111 may mirror current flowing through the second node N2and the third node N3 to the fourth node N4.

Further, the temperature compensation circuit 110 may include a thirdswitch S3 which is coupled between the third node N3 and a groundterminal VSS, a bipolar junction transistor (BJT) which is coupledbetween the fourth node N4 and a fifth node N5, and a second resistor R2which is coupled between the fifth node N5 and the ground terminal VSS.

The third switch S3 may be implemented as an NMOS transistor, and maygenerate a current between the third node N3 and the ground terminal VSSin response to the voltage outputted from the first amplifier AMP1. Forexample, when the voltage outputted from the first amplifier AMP1 ishigher than the threshold voltage of the third switch S3, the thirdswitch S3 is turned on, and thus a current path may be formed betweenthe third node N3 and the ground terminal VSS. For example, thepotential of the third node N3 may be adjusted depending on the turn-onlevel of the third switch S3. Therefore, when the third switch S3 isturned on, current is generated at the third node N3, and thus themirror circuit 111 coupled to the third node N3 may be operated.

The BJT may be implemented as an NPN-type transistor. For example, abase and a collector of the BJT may be coupled in common to the fourthnode N4, and an emitter of the BJT may be coupled to the fifth node N5.When the potential of the fourth node N4 transitions to a high logiclevel, a voltage inversely proportional to the temperature is formedacross both ends of the BJT, that is, the collector and the emitter, andthus a sub-voltage Vsub_temp inversely proportional to the temperaturemay be outputted through the fourth node N4.

The second amplifier AMP2 may compare the sub-voltage Vsub_temp with thevoltage of a sixth node N6, and then output a temperature voltage Vtemp.For example, the sub-voltage Vsub_temp may be applied to the positiveterminal (+) of the second amplifier AMP2, and the sixth node N6 may becoupled to the negative terminal (−) of the second amplifier AMP2. Thevoltage of the sixth node N6 may vary in response to both thetemperature voltage Vtemp outputted from the second amplifier AMP2 and avoltage outputted from the third amplifier AMP3. For example, thevoltage of the sixth node N6 may be determined by the division circuit120. The division circuit 120 may include a third resistor R3 coupledbetween the output node of the second amplifier AMP2 and the sixth nodeN6 and a fourth resistor R4 coupled between a seventh node N7, which isthe output node of the third amplifier AMP3, and the sixth node N6.

The third amplifier AMP3 may control the voltage of the seventh node N7in response to a first trimmed down voltage Vt1, outputted from thetrimming circuit 121, and a second trimmed down voltage Vt2, outputtedfrom the third amplifier AMP3. For example, the first trimmed downvoltage Vt1 may be applied to the positive terminal (+) of the thirdamplifier AMP3, and the second trimmed down voltage Vt2 may be appliedto the negative terminal (−) of the third amplifier AMP3. That is, thesecond trimmed down voltage Vt2 is fed back from the output of the thirdamplifier AMP3.

The trimming circuit 121 may be operated in response to the secondreference voltage Vref2, and may output the first trimmed down voltageVt1 which may vary depending on a preset trimming code Trim<a:0>, a highvoltage Vtop, and a low voltage Vbot. For example, the first trimmeddown voltage Vt1 may be a voltage different from the high voltage Vtopand the low voltage Vbot, or may be the high voltage Vtop or the lowvoltage Vbot. The trimming circuit 121 will be described in detailbelow.

FIG. 3 is a simplified block diagram schematically illustrating anexemplary configuration of the trimming circuit 121 of FIG. 2.

Referring to FIG. 3, the trimming circuit 121 may include a firstanalog-to-digital converter 1ADC and a second multiplexer MUX2. Thefirst analog-to-digital converter 1ADC may output a plurality of trimmeddown divided voltages Vtrim, a high voltage Vtop, and a low voltage Vbotin response to the second reference voltage Vref2. For example, the highvoltage Vtop and the low voltage Vbot may be voltages included in thetrimmed down divided voltages Vtrim. The first analog-to-digitalconverter 1ADC will be described in detail later with reference to FIG.4.

The second multiplexer MUX2 may output a voltage, selected from ad amongthe trimmed down divided voltages Vtrim, as a first trimmed down voltageVt1 in response to a trimming code Trim<a:0>.

FIG. 4 is a circuit diagram illustrating an exemplary configuration ofthe first analog-to-digital converter 1ADC of FIG. 3.

Referring to FIG. 4, a first analog-to-digital converter 1ADC may beoperated in response to a second reference voltage Vref2 and a trimmingcode Trim<a:0>, and may output a temperature voltage Vtemp varying withtemperature, a high voltage Vtop, and a low voltage Vbot.

For this operation, the first analog-to-digital converter 1ADC mayinclude a reference voltage transfer circuit Ref_C and a first resistorstring 1R_ST.

The reference voltage transfer circuit Ref_C may uniformly transfer asupply voltage VCCE to a ninth node N9 in response to the secondreference voltage Vref2. For example, the reference voltage transfercircuit Ref_C may include a fourth amplifier AMP4, a sixth switch S6,and a first capacitor CAP1. The fourth amplifier AMP4 may compare thesecond reference voltage Vref2 with the voltage of the ninth node N9,and may output a comparison result voltage through an eighth node N8.For example, the second reference voltage Vref2 may be applied to thenegative terminal (−) of the fourth amplifier AMP4, and the ninth nodeN9 may be coupled to the positive terminal (+) of the fourth amplifierAMP4. The sixth switch S6 may be implemented as a PMOS transistor forconnecting or disconnecting the terminal of the supply voltage VCCE andthe ninth node N9 in response to the potential of the eighth node N8.

The first capacitor CAP1 may be coupled between the eighth node N8 andthe ninth node N9.

Because of the configuration of the above-described reference voltagetransfer circuit Ref_C, the reference voltage transfer circuit Ref_C maybe operated as follows.

When the second reference voltage Vref2 is higher than the voltage ofthe ninth node N9, the fourth amplifier AMP4 may output a negativevoltage, so that the sixth switch S6 is turned on, and thus an amplifiedvoltage may be applied to the ninth node N9. When the second referencevoltage Vref2 is lower than the voltage of the ninth node N9, the fourthamplifier AMP4 may output a positive voltage, and thus the sixth switchS6 may be turned off. Since the sixth switch S6 is turned on or offdepending on the voltage of the eighth node N8 in this way, the voltageof the ninth node N9 may be varied, and a voltage gain may be decreasedby the first capacitor CAP1, and thus variation of the voltage of theninth node N9 may be decreased.

The first resistor string 1R_ST may include a plurality of stringresistors Rs coupled in series between the ninth node N9 and the groundterminal VSS. The string resistors Rs included in the first resistorstring 1R_ST may have the same resistance value. When a voltage isapplied to the ninth node N9, a current path through which current flowsfrom the ninth node N9 to the ground terminal VSS may be formed, andthus trimmed down divided voltages Vtrim having different voltage levelsmay be outputted depending on the locations of the nodes coupled betweenthe string resistors Rs. For example, as the location of each node iscloser to the reference voltage transfer circuit Ref_C, the level of atrimmed down divided voltage Vtrim may be increased. For example, thevoltage of a node closest to the ninth node N9 may be set to a highvoltage Vtop, and the voltage of a node farthest from the ninth node N9may be set to a low voltage Vbot. Nodes set to the nodes from which thehigh voltage Vtop and the low voltage Vbot are outputted may differaccording to the digital temperature sensing circuit 1000.

FIG. 5 is a circuit diagram illustrating an exemplary configuration ofthe code voltage generator 200 of FIG. 1.

Referring to FIG. 5, the code voltage generator 200 may be operated inresponse to a second reference voltage Vref2, and may output dividedvoltages Vtap<b:0> having various levels depending on a high voltageVtop and a low voltage Vbot.

For this, the code voltage generator 200 may include a high-voltagetransfer circuit 210, a second resistor string 2R_ST, and a low-voltagetransfer circuit 220.

The high-voltage transfer circuit 210 may include a fifth amplifierAMP5, a seventh switch S7, and a second capacitor CAP2. The fifthamplifier AMP5 may vary the voltage of a tenth node N10 in response tothe high voltage Vtop. The seventh switch S7 may be implemented as aPMOS transistor which can connect or disconnect a terminal to which thesecond reference voltage Vref2 is applied and the tenth node N10 inresponse to the output voltage of the fifth amplifier AMP5. The secondcapacitor CAP2 may be coupled between an additional output terminal ofthe fifth amplifier AMP5 and the tenth node N10. For example, of theoutput voltages of the fifth amplifier AMP5, a voltage applied to thesecond capacitor CAP2 may be lower than the voltage applied to theseventh switch S7. Of the output nodes of the fifth amplifier AMP5, anoutput node coupled to the second capacitor CAP2 may be maintained at astable voltage level by the second capacitor CAP2, thereby enabling thevoltage of the output node coupled to the seventh switch S7 to be stablymaintained.

The second resistor string 2R_ST may include a plurality of stringresistors Rs coupled in series between the high-voltage transfer circuit210 and the low-voltage transfer circuit 220. For example, the secondresistor string 2R_ST may include 16 string resistors Rs. In this case,the second resistor string 2R_ST may divide the voltage between thehigh-voltage transfer circuit 210 and the low-voltage transfer circuit220 and may output first to 15-th divided voltages Vtap<14:0> havingdifferent levels.

The string resistors Rs included in the second string 2R_ST have thesame resistance value, and may have a resistance value identical to ordifferent from that of the string resistors included in the firstresistor string 1R_ST of FIG. 4. The second resistor string 2R_ST may becoupled between the tenth node N10 of the high-voltage transfer circuit210 and an 11-th node N11 of the low-voltage transfer circuit 220. Whenthe voltage is applied to the tenth node N10, a current path throughwhich current flows from the tenth node N10 to the 11-th node N11 may beformed, and thus divided voltages (tap voltages) Vtap<b:0> havingdifferent voltage levels may be outputted depending on the locations ofthe nodes coupled between the string resistors Rs. For example, amongthe first to 15-th divided voltages Vtap<14:0>, the 15-th dividedvoltage Vtap<14> may have a highest level and the first divided voltageVtap<0> may have a lowest level. For example, the voltage level mayincrease in a direction from the first divided voltage Vtap<0> to thefifth divided voltage Vtap<14>.

The low-voltage transfer circuit 220 may include a sixth amplifier AMP6,an eighth switch S8, and a third capacitor CAP3. The sixth amplifierAMP6 may be supplied with a lowest voltage, among the voltages dividedby the second resistor string 2R_ST, and then operated to vary thevoltage of the 11-th node N11 in response to the low voltage Vbot. Forexample, since the low-voltage transfer circuit 220 may be coupledbetween the second resistor string 2R_ST and the ground terminal VSS, itmay maintain or decrease the voltage of the 11-th node N11 in responseto the low voltage Vbot. The low voltage Vbot may be applied to thenegative terminal (−) of the sixth amplifier AMP6, and the voltage ofthe 11-th node N11 may be applied to the positive terminal (+) of thesixth amplifier AMP6. The eighth switch S8 may be implemented as a PMOStransistor which may connect or disconnect the 11-th node N11 and theground terminal VSS in response to the output voltage of the secondamplifier AMP6. The third capacitor CAP3 may be coupled between anadditional output terminal of the sixth amplifier AMP6 and the 11-thnode N11. For example, of the output voltages of the sixth amplifierAMP6, a voltage applied to the third capacitor CAP3 may be lower than avoltage applied to the eighth switch S8. Of the output nodes of thesixth amplifier AMP6, an output node coupled to the third capacitor CAP3may be maintained at a stable voltage level by the third capacitor CAP3,thus enabling the voltage of the output node coupled to the eighthswitch S8 to be stably maintained.

The above-described fifth amplifier AMP5 and the sixth amplifier AMP6may be configured in different structures, which will be described indetail below with reference to FIGS. 6 and 7.

FIG. 6 is a circuit diagram illustrating an exemplary configuration ofthe fifth amplifier AMP5 of FIG. 5.

Referring to FIG. 6, the fifth amplifier AMP5 may include ninth to 18-thswitches S9 to S18. The ninth to 13-th switches S9 to S13 and the 14-thto 18-th switches S14 to S18 may be coupled in parallel between a supplyvoltage terminal VCCE and a ground terminal VSS.

In detail, the ninth and tenth switches S9 and S10 may be coupled inseries between the supply voltage terminal VCCE and a 13-th node N13,and the 14-th and 15-th switches S14 and S15 may be coupled in seriesbetween the supply voltage terminal VCCE and a 16-th node N16. All ofthe ninth, tenth, 14-th and 15-th switches S9, S10, S14 and S15 may beimplemented as PMOS transistors. Gates of the ninth and 14-th switchesS9 and S14 may be coupled in common to a 12-th node N12, and the 12-thnode N12 may be coupled to the 13-th node N13. Therefore, the ninth and14-th switches S9 and S14 may be turned on or off in response to thevoltage applied to the 13-th node N13. Gates of the tenth and 15-thswitches S10 and S15 may be coupled in common to each other. Since boththe tenth and 15-th switches S10 and S15 are implemented as PMOStransistors, they may always remain turned on. A 15-th node connectingthe 14-th and 15-th switches S14 and S15 to each other may be coupled tothe second capacitor CAP2.

The 11-th switch S11 may be implemented as an NMOS transistor which mayconnect or disconnect the 13-th node N13 and a 14-th node N14 inresponse to the voltage of the tenth node N10 of FIG. 5. The 12-th and13-th switches S12 and S13 may be implemented as NMOS transistorscoupled in series between the 14-th node N14 and the ground terminalVSS.

The 16-th switch S16 may be implemented as an NMOS transistor which mayconnect or disconnect the 16-th node N16 and the 14-th node N14 inresponse to the high voltage Vtop. The 16-th node N16 between the 15-thand 16-th switches S15 and S16 may be coupled to the gate of the seventhswitch S7 of FIG. 5. That is, the output terminals of the fifthamplifier AMP5 may be the 15-th and 16-th nodes N15 and N16, and theseventh switch S7 may be turned on or off by the voltage outputtedthrough the 16-th node N16 of the output terminals. The voltage appliedto the 16-th node N16 may have a level less than the voltage applied tothe 15-th node N15 by the threshold voltage of the 15-th switch S15.

The 17-th and 18-th switches S17 and S18 may be implemented as NMOStransistors coupled in series between the 14-th node N14 and the groundterminal VSS.

Gates of the 12-th and 17-th switches S12 and S17 may be coupled to eachother, and gates of the 13-th and 18-th switches S13 and S18 may becoupled to each other.

FIG. 7 is a circuit diagram illustrating an exemplary configuration ofthe sixth amplifier AMP6 of FIG. 5.

Referring to FIG. 7, the sixth amplifier AMP6 may include 19-th to 28-thswitches S19 to S28. The 19-th to 23-rd switches S19 to S23 and the24-th to 28-th switches S24 to S28 may be coupled in parallel between asupply voltage terminal VCCE and a ground terminal VSS.

In detail, the 19-th and 20-th switches S19 and S20 may be coupled inseries between the supply voltage terminal VCCE and a 17-th node N17,and the 24-th and 25-th switches S24 and S25 may be coupled in seriesbetween the supply voltage terminal VCCE and a 19-th node N19. All ofthe 19-th, 20-th, 24-th and 25-th switches S19, S20, S24 and S25 may beimplemented as PMOS transistors. Gates of the 19-th and 24-th switchesS19 and S24 may be coupled to each other. Therefore, the 19-th and 24-thswitches S19 and S24 may always remain turned on. Gates of the 20-th and25-th switches S20 and S25 may be coupled in common to each other. Sinceboth the 20-th and 25-th switches S20 and S25 are implemented as PMOStransistors, they may always remain turned on.

A gate of the 21-st switch S21 may be implemented as a PMOS transistorwhich is turned on or off in response to the potential of the 11-th nodeN11 of FIG. 5. The 22-nd and 23-rd switches S22 and S23 may beimplemented as NMOS transistors coupled in series between an 18-th nodeN18 and the ground terminal VSS. A gate of the 23-rd switch S23 may becoupled to the 18-th node N18.

The 26-th switch S26 may be implemented as a PMOS transistor which mayconnect or disconnect the 19-th node N19 and a 20-th node N20 inresponse to the low voltage Vbot.

The 27-th and 28-th switches S27 and S28 may be implemented as NMOStransistors coupled in series between a 20-th node N20 and the groundterminal VSS. A gate of the 27-th switch S27 may be coupled to a gate ofthe 22-nd switch S22. A gate of the 28-th switch S28 may be coupled tothe 18-th node N18. That is, the gates of the 23-rd and 28-th switchesS23 and S28 may be coupled in common to the 18-th node N18.

Further, a 21-st node N21 between the 27-th and 28-th switches S27 andS28 may be coupled to the third capacitor CAPS of FIG. 5. The voltageapplied to the 21-st node N21 may have a level less than the voltageapplied to the 20-th node N20 by the threshold voltage of the 21-stswitch S21.

FIG. 8 is a simplified block diagram schematically illustrating anexemplary configuration of the mode selector 300 of FIG. 1.

Referring to FIG. 8, the mode selector 300 may include amulti-digital-to-analog converter MDAC, a second analog-to-digitalconverter 2ADC, and an adder ADDER.

The multi-digital-to-analog converter MDAC may output a positive voltageVMDAC_P and a negative voltage VMDAC_N in response to the slow modeselect signal SMSEL, first sub-divided voltages Vtap1# being a part ofdivided voltages Vtap<b:0>, and a temperature voltage Vtemp. Forexample, the multi-digital-to-analog converter MDAC may be enabled onlyin a slow mode. For example, the multi-digital-to-analog converter MDACmay be operated only in the slow mode.

Among the divided voltages Vtap<b:0>, remaining second sub-dividedvoltages Vtap2# other than the first sub-divided voltages Vtap1# may beinputted to the 2ADC.

The 2ADC may output the first code COMP1<c:0> or an additional codeCODE_add<d:0> in response to the mode select signal SMSEL or FMSEL, thesecond sub-divided voltages Vtap2#, the temperature voltage Vtemp, andthe positive voltage VMDAC_P or the negative voltage VMDAC_N. The firstcode COMP1<c:0> may be outputted in response to the fast mode selectsignal FMSEL, and the additional code CODE_add<d:0> may be outputted inresponse to the slow mode select signal SMSEL.

The number of bits of the first code COMP1<c:0> may be greater than thenumber of bits of the additional code CODE_add<d:0>. For example, sincethe first code COMP1<c:0> is outputted in the fast mode, it may beoutputted as a 4-bit code within a short period of time. However, theadditional code CODE_add<d:0> may require a long time to converttemperature into a digital signal in order to realize high resolution,and may be outputted as a plurality of 2-bit codes. Therefore, in theslow mode, the additional code CODE_add<d:0> may be outputted in theform of a plurality of additional codes CODE_add<d:0> rather than beingused as the temperature code. The outputted plurality of additionalcodes CODE_add<d:0> may be added by the adder ADDER during multiplecycles, and thereafter the added code may be outputted as the secondcode COMP2<e:0>.

The adder ADDER may be operated in response to the mode select signalSMSEL. For example, the adder ADDER may be enabled in response to theslow mode select signal SMSEL. For example, the adder ADDER may receiveeach additional code CODE_add<d:0> in response to the slow mode selectsignal SMSEL, may add received additional codes CODE_add<d:0> receivedwhile multiple cycles in which the additional codes CODE_add<d:0> arereceived are executed, and may output a resulting additional codeCODE_add<d:0> as the second code COMP2<e:0>. For example, the adderADDER may add one bit of the additional code CODE_add<d:0> received in afirst cycle to one bit of the additional code CODE_add<d:0> received ina second cycle. In this way, the adder ADDER may generate the secondcode COMP2<e:0> composed of a plurality of bits by adding the pluralityof 2-bit additional codes CODE_add<d:0> received in respective cycles.Further, the adder ADDER may output an end signal END_S whenever thesecond code COMP2<e:0> is outputted. That is, when a preset number ofcycles are executed and the second code COMP2<e:0> having a presetnumber of bits is generated, the adder ADDER may output the second codeCOMP2<e:0>.

FIG. 9 is a circuit diagram illustrating an exemplary configuration ofthe multi-digital-to-analog converter MDAC of FIG. 8.

Referring to FIG. 9, the multi-digital-to-analog converter MDAC mayreceive the temperature voltage Vtemp and the first sub-divided voltagesVtap1#, and may output the positive voltage VMDAC_P or the negativevoltage VMDAC_N in response to the slow mode select signal SMSEL.

For this operation, the MDAC may include third and fourth multiplexersMUX3 and MUX4, a plurality of first and second clock switches CS1 andCS2 which are turned on or off in response to a clock CLK, a pluralityof capacitors CAPm, and a seventh amplifier AMP7. The third multiplexerMUX3 may receive a reference divided voltage included in the firstsub-divided voltages Vtap1# and the voltage of a 22-nd node, and mayoutput a voltage selected from the received voltages to a 23-rd nodeN23. For example, the reference divided voltage may be a voltagecorresponding to a median value, among the divided voltages Vtap<b:0>outputted from the code voltage generator 200. For example, it isassumed that the code voltage generator 200 outputs first to 15-thdifferent voltages Vtap<14:0> and that the first divided voltage Vtap<0>has a lowest level and the divided voltages have gradually increasedlevels in a direction from the first divided voltage Vtap<0> to the15-th divided voltage Vtap<14>. Among the first to 15-th dividedvoltages Vtap<14:0>, the eighth divided voltage Vtap<7> may correspondto a median value.

The fourth multiplexer MUX4 may receive the temperature voltage Vtempand the voltage of a 24-th node N24, and output a voltage selected fromthe received voltages to a 25-th node N25.

Two first clock switches CS1 may be coupled in parallel to the 23-rdnode N23, and two first clock switches CS1 may also be coupled inparallel to the 25-th node N25. The 25-th node N25 is not coupled to the23-rd node N23.

The first clock switches CS1 may be turned on or off depending on aninternal clock CLK that is generated in the digital temperature sensingcircuit 1000 or an internal clock CLK generated in a memory systemincluding the digital temperature sensing circuit 1000.

Referring to timing diagram 900 of FIG. 9, the first clock switches CS1may be turned on when the internal clock CLK goes high (H). One firstclock switch CS1 coupled to the 23-rd node N23 may be coupled betweenthe 23-rd node N23 and a 26-th node N26, and another first clock switchCS1 may be coupled between the 23-rd node N23 and a correspondingcapacitor CAPm. One first clock switch CS1 coupled to the 25-th node N25may be coupled between the 25-th node N25 and a 27-th node N27, andanother first clock switch CS1 may be coupled between the 25-th node N25and a corresponding capacitor CAPm.

One capacitor CAPm may be coupled between the 26-th node N26 and a 28-thnode N28, and an additional capacitor CAPm may also be coupled betweenthe 27-th node N27 and a 29-th node N29. The capacitors CAPm coupled tothe 23-rd node N23 may be coupled in common to the 28-th node N28, andthe capacitors CAPm coupled to the 25-th node N25 may be coupled incommon to the 29-th node N29. Two first clock switches CS1 may becoupled between the 28-th node N28 and the 29-th node N29. The eighthdivided voltage Vtap<7> may be applied to a node between the first clockswitches CS1 that are coupled between the 28-th node N28 and the 29-thnode N29.

A plurality of second clock switches CS2 may be coupled in parallel tothe 26-th node N26. The second clock switches CS2 may be turned on oroff depending on the same internal clock CLK as the first clock switchesCS1. However, the second clock switches CS2 may be operated in a wayopposite to the first clock switches CS1.

Referring to the timing diagram 900 of FIG. 9, the second clock switchesCS2 may be turned on when the internal clock CLK goes low (L).Alternatively, the first clock switches CS1 may be designated to beturned on at the low logic level L of the internal clock CLK, and thesecond clock switches CS2 may be designated to be turned on at the highlogic level H of the internal clock CLK. In the embodiment of FIG. 9,the first clock switches CS1 are turned on at the high logic level H ofthe internal clock CLK, and the second clock switches CS2 are turned onat the low logic level L of the internal clock CLK.

Changeover switches that are turned on or turned off in response toanalog-to-digital conversion codes ADC<1:0> may be coupled to respectivesecond clock switches CS2 coupled to the 26-th node N26, and differentdivided voltages may be applied to the respective changeover switches.For example, one of the changeover switches may be coupled between aterminal to which a fourth divided voltage Vtap<3> is applied and onesecond clock switch CS2, another changeover switch may be coupledbetween a terminal to which an eighth divided voltage Vtap<7> is appliedand another second clock switch CS2, and the other changeover switch maybe coupled between a terminal to which a tenth divided voltage Vtap<9>is applied and the other second clock switch CS2. The changeover switchto which the fourth divided voltage Vtap<3> is applied may be turned onwhen the analog-to-digital conversion code is ‘10’, the changeoverswitch to which the eighth divided voltage Vtap<7> is applied may beturned on when the analog-to-digital conversion code is ‘01’, and thechangeover switch to which the tenth divided voltage Vtap<9> is appliedmay be turned on when the analog-to-digital conversion code is ‘00.’ Forexample, the analog-to-digital conversion codes ADC<1:0> may beadditional codes CODE_add<d:0> outputted from the analog-to-digitalconverter 2ADC. For example, each additional code CODE_add<d:0> may be acode composed of 2 bits.

Second clock switches CS2 and changeover switches coupled to the 26-thnode N26 may also be coupled in the same structure to the 27-th nodeN27. Among the changeover switches coupled to the 27-th node N27, forexample, the changeover switch to which the fourth divided voltageVtap<3> is applied may be turned on when the analog-to-digitalconversion code is ‘00’, the changeover switch to which the eighthdivided voltage Vtap<7> is applied may be turned on when theanalog-to-digital conversion code is ‘01’, and the changeover switch towhich the tenth divided voltage Vtap<9> is applied may be turned on whenthe analog-to-digital conversion code is ‘10’.

The seventh amplifier AMP7 may be enabled in response to the slow modeselect signal SMSEL. The seventh amplifier AMP7 may output a positivevoltage VMDAC_P and a negative voltage VMDAC_N through a positive outputterminal (+) and a negative output terminal (−) depending on voltagesapplied to a positive input terminal (+) and a negative input terminalH. For example, the voltage of the 28-th node N28 or a 30-th node N30may be applied to the positive input terminal (+) of the seventhamplifier AMP7. When the second clock switches CS2 are turned on, thevoltage of the 28-th node N28 may be applied to the positive inputterminal (+) of the seventh amplifier AMP7, whereas when the first clockswitches CS1 are turned on, the voltage of the 30-th node N30 may beapplied to the positive input terminal (+) of the seventh amplifierAMP7. The voltage of the 29-th node N29 or a 31-st node N31 may beapplied to the negative input terminal (−) of the seventh amplifierAMP7. When the second clock switches CS2 are turned on, the voltage ofthe 29-th node N29 may be applied to the negative input terminal (−) ofthe seventh amplifier AMP7, whereas when the first clock switches CS1are turned on, the voltage of the 31-st node N31 may be applied to thenegative input terminal (−) of the seventh amplifier AMP7. Therefore,one first clock switch CS1 may be coupled between the positive inputterminal (+) of the seventh amplifier AMP7 and the 30-th node N30, andanother first clock switch CS1 may be coupled between the negative inputterminal (−) of the seventh amplifier AMP7 and the 31-st node N31.

A capacitor CAPm may be coupled between the 30-th node N30 and the 22-ndnode N22, wherein the CAPm coupled to the 22-nd node N22 may be coupledto a node between one of the first clock switches CS1 coupled to the23-rd node N23, i.e., a first clock switch CS1 which is not coupled tothe 26-th node N26, and the capacitor CAPm.

A capacitor CAPm may be coupled between the 31-st node N31 and the 24-thnode N24, wherein the CAPm coupled to the 24-th node N24 may be coupledto a node between one of the first clock switches CS1 coupled to the25-th node N25, that is, a first clock switch CS1 which is not coupledto the 27-th node N27, and the capacitor CAPm.

One second clock switch CS2 may be coupled between the 30-th node N30and a 32-nd node N32, and another clock switch CS2 may be coupledbetween the 31-st node N31 and the 32-nd node N32. The eighth dividedvoltage Vtap<7> may be applied to the 32-nd node N32.

The above-described multi-digital-to-analog converter MDAC may beenabled in response to the slow mode select signal SMSEL. As the firstand second clock switches CS1 and CS2 are alternately turned on inresponse to the internal clock CLK, the MDAC may output a positivevoltage VMDAC_P and a negative voltage VMDAC_N.

FIG. 10 is a circuit diagram illustrating an exemplary configuration ofthe second analog-to-digital converter 2ADC of FIG. 8.

Referring to FIG. 10, the second analog-to-digital converter 2ADC mayoutput first codes COMP1<0>, <1>, . . . , <b>, <b+1>, . . . , <14> oradditional codes CODE_add<a>, <a+1>, . . . in response to the modeselect signal SMSEL or FMSEL, the second sub-divided voltages Vtap2#,the positive voltage VMDAC_P, and the negative voltage VMDAC_N. Forexample, the second analog-to-digital converter 2ADC may include anadditional code output circuit SM, first code output circuits FM1 andFM2, and multiplexers 1010. Individual circuits will be described indetail below.

The additional code output circuit SM and the first code output circuitsFM1 and FM2 may include a plurality of select amplifiers SAMP0 toSAMP14. For example, the number of select amplifiers SAMP0 to SAMP14 maybe identical to the number of first to 15-th divided voltagesVtap<14:0>. For example, the first to 15-th divided voltages Vtap<14:0>may be respectively applied to the select amplifiers SAMP0 to SAMP14.

The select amplifiers SAMP0, SAMP1, . . . , SAMPb, SAMPb+1, . . . ,SAMP14 included in the first code output circuits FM1 and FM2 may beenabled in response to a fast mode select signal. Each of the selectamplifiers SAMP0, SAMP1, . . . , SAMPb, SAMPb+1, . . . , SAMP14 includedin the first code output circuits FM1 and FM2 may include one positiveinput terminal (+) and one negative input terminal (−), and may includeone output terminal. For example, a temperature voltage Vtemp may beapplied in common to the positive input terminals (+) of the selectamplifiers SAMP0, SAMP1, . . . , SAMPb, SAMPb+1, . . . , SAMP14 includedin the first code output circuits FM1 and FM2, and the divided voltagesVtap<0>, Vtap<1>, . . . , Vtap<b>, Vtap<b+1>, . . . , Vtap<14>respectively corresponding to the select amplifiers SAMP0, SAMP1, . . ., SAMPb, SAMPb+1, . . . , SAMP14 may be applied to the negative inputterminals (−) of the select amplifiers. The select amplifiers SAMP0,SAMP1, . . . , SAMPb, SAMPb+1, . . . , SAMP14 may output first codesCOMP1<0>, <1>, . . . , <b>, <b+1>, . . . , <14> in response to thetemperature voltage Vtemp and the divided voltages Vtap<0>, Vtap<1>, . .. , Vtap<b>, Vtap<b+1>, . . . , Vtap<14>.

The select amplifiers SAMPa, SAMPa+1, . . . included in the additionalcode output circuit SM may be enabled in response to the slow modeselect signal SMSEL. Each of the select amplifiers SAMPa, SAMPa+1, . . .included in the additional code output circuit SM may include twopositive input terminals (+) and two negative input terminals (−), andmay include one output terminal. For example, voltages outputted fromthe 1010 may be applied to the first positive input terminals (+), firstnegative input terminals (−), and second positive input terminals (+) ofthe select amplifiers SAMPa, SAMPa+1, . . . included in the additionalcode output circuit SM. The divided voltages Vtap<a>, Vtap<a+1>, . . .respectively corresponding to the select amplifiers SAMPa, SAMPa+1, . .. included in the additional code output circuit SM may be applied tothe second negative input terminals (−) of the select amplifiers.

The a-th select amplifier SAMPa is described below by way of example.

The MUX 1010 coupled to the first positive input terminal (+) of thea-th select amplifier SAMPa may transfer a voltage selected from thepositive voltage VMDAC_P and the temperature voltage Vtemp to the firstpositive input terminal (+). The MUX 1010 coupled to the first negativeinput terminal (−) may transfer a voltage selected from the negativevoltage VMDAC_N and the temperature voltage Vtemp to the first negativeinput terminal (−). The MUX 1010 coupled to the second positive inputterminal (+) may transfer a voltage selected from the a+1-th dividedvoltage Vtap<a> and the eighth divided voltage Vtap<7> to the secondpositive input terminal (+). For example, the eighth divided voltageVtap<7> may be a voltage corresponding to a median value, among thedivided voltages Vtap<b:0> outputted from the code voltage generator200. The a+1-th divided voltage Vtap<a> applied to the MUX 1010 coupledto the second positive input terminal (+) is also applied to the secondnegative input terminal (−).

As in the case of the coupling configuration of the above-described a-thselect amplifier SAMPa, remaining select amplifiers SAMPa+1, . . .included in the additional code output circuit SM may be configured inthe same manner, and divided voltages corresponding to respective selectamplifiers, instead of the a+1-th divided voltage Vtap<a>, may beapplied to the remaining select amplifiers SAMPa+1, . . . ,respectively. The select amplifiers SAMPa, SAMPa+1, . . . may output theadditional codes CODE_add<a>, <a+1>, . . . , respectively, in responseto the temperature voltage Vtemp, the positive voltage VMDAC_P, thenegative voltage VMDAC_N, and the divided voltages Vtap<a>, Vtap<a+1>, .. . .

Although it is illustrated in FIG. 10 that the select amplifies SAMP0,SAMP1, . . . , and SAMPb, SAMPb+1, . . . , SAMP14 respectively includedin the first code output circuits FM1 and FM2 are sequentially arranged,and that the select amplifiers SAMPa, SAMPa+1, . . . included in theadditional code output circuit SM are sequentially arranged between thefirst code output circuits FM1 and FM2, the array order of the selectamplifies SAMPa, SAMPa+1, included in the additional code output circuitSM and the select amplifies SAMP0, SAMP1, . . . and SAMPb, SAMPb+1, . .. , SAMP14 included in the first code output circuits FM1 and FM2 may bechanged.

FIG. 11 is a simplified block diagram for explaining the operation ofthe adder ADDER of FIG. 8.

Referring to FIG. 11, the adder ADDER may be enabled in response to aslow mode select signal SMSEL. For example, the adder ADDER may outputthe second code COMP2<e:0> by adding additional codes CODE_add<d:0>received over multiple cycles. For example, a time C1 at which a firstcycle starts and a time C2 at which a ninth cycle, i.e., a last cycle,ends may be set in advance, and additional codes CODE_add<d:0> may bereceived in respective cycles. When all of the additional codesCODE_add<d:0> are received in the last ninth cycle (denoted with “9cycle” in FIG. 11), the adder ADDER may output an end signal END_Sindicating that all of the set cycles have been executed. That is, atemperature value is measured in each cycle, and additional codesCODE_add<d:0> are generated based on respective measured temperaturevalues, and thus a second code COMP2<e:0> having higher resolution thanthat of the first code COMP1<c:0> may be outputted in a slow mode. Forexample, the adder ADDER may receive 2-bit additional codesCODE_add<d:0> in each cycle, and some of the additional codesCODE_add<d:0> received in respective cycles may be added to generate thesecond code COMP2<e:0>. For example, it is assumed that additional codesCODE_add<d:0> received in the first cycle (denoted with “1 cycle” inFIG. 11) are ‘1’ and ‘2’, and that additional codes CODE_add<d:0>received in the second cycle (denoted with “2 cycle” in FIG. 11) are ‘3’and ‘4.’ For example, data of ‘1’ may be data of the second codeCOMP2<0>. Then, data of ‘2’ and data of ‘3’ may be added, and the addeddata may become data of the second code COMP2<1>. Therefore, assumingthat pieces of data received in the last ninth cycle (denoted with “9cycle” in FIG. 11) are ‘17’ and ‘18’, data of ‘18’ may become data ofthe second code COMP2<e>. In this way, when the addition operation onadditional codes CODE_add<d:0> received in respective cycles isterminated, the added data may be outputted as the second codeCOMP2<e:0>.

Accordingly, the first MUX 400 of FIG. 1 may receive either of the firstcode COMP1<c:0> and the second code COMP2<e:0> having differentresolutions depending on the mode select signal SMSEL or FMSEL, and mayoutput the received code as a temperature code T_CODE.

FIG. 12 is a simplified block diagram illustrating a memory systemincluding the digital temperature sensing circuit according to anembodiment of the present disclosure.

Referring to FIG. 12, the above-described digital temperature sensingcircuit 1000 may be included in a memory system 2000. For example, thememory system 2000 may include a memory device 1100 which stores data, amemory controller 1200 which controls the memory device 1100, and thedigital temperature sensing circuit 1000 which measures the temperatureof the memory system and outputs a temperature code T_CODE to the memorycontroller 1200.

When operating voltages are controlled by compensating for the internaltemperature of the memory system 2000, the memory controller 1200 mayoutput a fast mode select signal FMSEL to the digital temperaturesensing circuit 1000.

For example, when the internal temperature is compensated for, it may becompensated for in real time only if a code capable of varyingtemperature in response to a temperature change is rapidly outputted,and thus the memory controller 1200 may transmit the fast mode selectsignal FMSEL to the digital temperature sensing circuit 1000. Since thedigital temperature sensing circuit 1000 may rapidly output thetemperature code T_CODE in response to the fast mode select signalFMSEL, the memory controller 1200 may rapidly respond to the temperaturechange. For example, the internal temperature may be the temperature ofthe memory system 2000, the temperature of the memory controller 1200,or the temperature of the memory device 1100.

When a temperature value is provided to the memory system 2000, accuratetemperature information must be provided, and thus the memory controller1200 may transmit a slow mode select signal SMSEL to the digitaltemperature sensing circuit 1000. The digital temperature sensingcircuit 1000 may output a temperature code T_CODE, which has anoperating time longer than that of the fast mode, but has a resolutionhigher than that of the fast mode, in response to the slow mode selectsignal, thus improving the reliability of temperature values.

Although, in the above-described embodiment, the fast mode and the slowmode have been described, a low-resolution mode and a high-resolutionmode in addition to the fast and slow modes may be included as variousmodes, or alternatively, three or more modes may be included as variousmodes.

FIG. 13 is a simplified block diagram illustrating an embodiment of amemory system 30000 including the digital temperature sensing circuit ofFIG. 1.

Referring to FIG. 13, the memory system 30000 may be implemented as acellular phone, a smart phone, a tablet PC, a personal digital assistant(PDA) or a wireless communication device. The memory system 30000 mayinclude a memory device 1100, a digital temperature sensing circuit(DTS) 1000 which may output a temperature value as a temperature codethat is a digital code, and a memory controller 1200 which may controlthe digital temperature sensing circuit 1000 and the memory device 1100.The memory controller 1200 may control a data access operation for thememory device 1100, for example, a program operation, an erase operationor a read operation, under the control of a processor 3100. Further, thememory controller 1200 may receive temperature codes having differentresolutions by controlling the digital temperature sensing circuit 1000in various modes. Data programmed to the memory device 1100 may beoutputted via a display 3200 under the control of the memory controller1200 and/or the processor 3100.

A radio transceiver 3300 may exchange radio signals through an antennaANT. For example, the radio transceiver 3300 may change a radio signalreceived through the antenna ANT into a signal which may be processed inthe processor 3100. Therefore, the processor 3100 may process a signaloutputted from the radio transceiver 3300 and transmit the processedsignal to the memory controller 1200 or the display 3200. The memorycontroller 1200 may transmit the signal processed by the processor 3100to the memory device 1100. Furthermore, the radio transceiver 3300 maychange a signal outputted from the processor 3100 into a radio signal,and output the changed radio signal to an external device through theantenna ANT. An input device 3400 may be used to input a control signalfor controlling the operation of the processor 3100 or data to beprocessed by the processor 3100. The input device 3400 may beimplemented as a pointing device such as a touch pad or a computermouse, a keypad, a keyboard, or any combination thereof. The processor3100 may control the operation of the display 3200 such that dataoutputted from the memory controller 1200, data outputted from the radiotransceiver 3300, or data outputted from the input device 3400 isoutputted via the display 3200.

In various embodiments, the memory controller 1200 capable ofcontrolling the operation of the memory device 1100 may be implementedas a part of the processor 3100 or a chip provided separately from theprocessor 3100.

FIG. 14 is a simplified block diagram illustrating another embodiment ofa memory system 40000 including the digital temperature sensing circuit1000 of FIG. 1.

Referring to FIG. 14, the memory system 40000 may be embodied in apersonal computer, a tablet PC, a net-book, an e-reader, a personaldigital assistant (PDA), a portable multimedia player (PMP), an MP3player, or an MP4 player.

The memory system 40000 may include a memory device 1100, the digitaltemperature sensing circuit (DTS) 1000 which may output a temperaturevalue as a temperature code that is a digital code, and a memorycontroller 1200 which may control the digital temperature sensingcircuit 1000 and the memory device 1100. Further, the memory controller1200 may receive temperature codes having different resolutions bycontrolling the digital temperature sensing circuit 1000 in variousmodes.

A processor 4100 may output data stored in the memory device 1100 via adisplay 4300 according to data inputted from an input device 4200. Forexample, the input device 4200 may be implemented as a pointing devicesuch as a touch pad or a computer mouse, a keypad, a keyboard, or acombination thereof.

The processor 4100 may control the overall operation of the memorysystem 40000 and control the operation of the memory controller 1200. Inan embodiment, the memory controller 1200 capable of controlling theoperation of the memory device 1100 may be implemented as a part of theprocessor 4100 or a chip provided separately from the processor 4100.

FIG. 15 is a simplified block diagram illustrating yet anotherembodiment of a memory system 50000 including the digital temperaturesensing circuit 1000 of FIG. 1.

Referring to FIG. 15, the memory system 50000 may be embodied in animage processing device, e.g., a digital camera, a mobile phone providedwith a digital camera, a smartphone provided with a digital camera, or atablet PC provided with a digital camera.

The memory system 50000 may include a memory device 1100, the digitaltemperature sensing circuit (DTS) 1000 which may output a temperaturevalue as a temperature code that is a digital code, and a memorycontroller 1200 which may control the digital temperature sensingcircuit 1000 and the memory device 1100. Further, the memory controller1200 may receive temperature codes having different resolutions bycontrolling the digital temperature sensing circuit 1000 in variousmodes.

An image sensor 5200 of the memory system 50000 may convert an opticalimage into digital signals. The converted digital signals may betransmitted to a processor 5100 or the memory controller 1200. Under thecontrol of the processor 5100, the converted digital signals may beoutputted via a display 5300 or stored in the memory device 1100 throughthe memory controller 1200. Data stored in the memory device 1100 may beoutputted via the display 5300 under the control of the processor 5100or the memory controller 1200.

In various embodiments, the memory controller 1200 capable ofcontrolling the operation of the memory device 1100 may be implementedas a part of the processor 5100, or a chip provided separately from theprocessor 5100.

FIG. 16 is a simplified block diagram illustrating yet anotherembodiment of a memory system 70000 including the digital temperaturesensing circuit 1000 of FIG. 1.

Referring to FIG. 16, the memory system 70000 may be implemented as amemory card or a smart card. The memory system 70000 may include amemory device 1100, the digital temperature sensing circuit (DTS) 1000,a memory controller 1200, and a card interface 7100.

The memory controller 1200 may control data exchange between the memorydevice 1100 and the card interface 7100. In an embodiment, the cardinterface 7100 may be, but is not limited to, a secure digital (SD) cardinterface or a multi-media card (MMC) interface.

The card interface 7100 may interface data exchange between a host 60000and the memory controller 1200 according to a protocol of the host60000. In an embodiment, the card interface 7100 may support a universalserial bus (USB) protocol and an inter-chip (IC)-USB protocol. Forexample, the card interface may refer to hardware capable of supportinga protocol which is used by the host 60000, software installed in thehardware, or a signal transmission method.

When the memory system 70000 is coupled to a host interface 6200 of thehost 60000, such as a PC, a tablet PC, a digital camera, a digital audioplayer, a mobile phone, console video game hardware or a digital set-topbox, the host interface 6200 may perform data communication with thememory device 1100 through the card interface 7100 and the memorycontroller 1200 under the control of a microprocessor (μP) 6100.

The digital temperature sensing circuit according to the presentdisclosure may output temperature codes by selectively varyingresolution depending on various modes using a single temperature sensingcircuit, thus reducing an area occupied by the digital temperaturesensing circuit.

While the exemplary embodiments of the present disclosure have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible. Therefore, the scope of the present disclosure must be definedby the appended claims and equivalents of the claims rather than by thedescription preceding them.

What is claimed is:
 1. A digital temperature sensing circuit,comprising: a temperature voltage generator configured to generate atemperature voltage varying with a temperature in response to a firstreference voltage, divide a supply voltage in response to a secondreference voltage, and generate a high voltage and a low voltage; a codevoltage generator configured to divide the second reference voltagebased on the high voltage and the low voltage and output dividedvoltages having different voltage levels; and a mode selector suppliedwith the temperature voltage and the divided voltages, and configured tooutput a first code or a second code in response to a mode selectsignal, wherein the first code and the second code have differentnumbers of bits.
 2. The digital temperature sensing circuit according toclaim 1, wherein the temperature voltage generator is configured tooutput the temperature voltage, the high voltage, and the low voltage inresponse to the first reference voltage and a trimming code.
 3. Thedigital temperature sensing circuit according to claim 2, wherein thetemperature voltage generator comprises: a first amplifier configured tocompare the first reference voltage with a first feedback voltage andthen output a comparison result voltage; a temperature compensationcircuit configured to output a sub-voltage inversely proportional to thetemperature in response to the comparison result voltage; a secondamplifier configured to compare the sub-voltage with a divided voltageand then output the temperature voltage; a trimming circuit suppliedwith the second reference voltage, and configured to output a firsttrimmed down voltage in response to the trimming code; a third amplifierconfigured to output a second feedback voltage in response to the firsttrimmed down voltage; and a division circuit configured to divide thesecond feedback voltage and then output the divided voltage.
 4. Thedigital temperature sensing circuit according to claim 3, wherein thetemperature compensation circuit comprises: a first switch configured togenerate a current in response to the comparison result voltage; amirror circuit configured to mirror the current to an output node; and abipolar junction transistor configured to output a voltage inverselyproportional to the temperature through the output node.
 5. The digitaltemperature sensing circuit according to claim 4, wherein the bipolarjunction transistor is configured to, when a potential of the outputnode transitions to a high logic level, form a voltage inverselyproportional to the temperature across a collector and an emitter of thebipolar junction transistor.
 6. The digital temperature sensing circuitaccording to claim 3, wherein the trimming circuit comprises: a firstanalog-to-digital converter configured to output trimmed down dividedvoltages by dividing the supply voltage depending on the secondreference voltage; and a multiplexer configured to output a voltage,selected from among the trimmed down divided voltages, as the firsttrimmed down voltage in response to the trimming code.
 7. The digitaltemperature sensing circuit according to claim 6, wherein the firstanalog-to-digital converter comprises: a reference voltage transfercircuit configured to uniformly transfer the supply voltage to an outputterminal in response to the second reference voltage; and a firstresistor string coupled between the output terminal of the referencevoltage transfer circuit and a ground terminal, and configured to dividethe supply voltage, outputted from the reference voltage transfercircuit, and output divided voltages as the trimmed down dividedvoltages.
 8. The digital temperature sensing circuit according to claim7, wherein the reference voltage transfer circuit comprises: a fourthamplifier configured to compare the second reference voltage with avoltage of the output node and then output a comparison result voltage;a second switch configured to connect or disconnect the output terminalof the reference voltage transfer circuit and a supply voltage terminalsupplying the supply voltage, in response to the comparison resultvoltage; and a first capacitor coupled between an output terminal of thefourth amplifier and the output terminal of the reference voltagetransfer circuit.
 9. The digital temperature sensing circuit accordingto claim 7, wherein the first resistor string comprises a plurality ofstring resistors coupled in series between the output terminal of thereference voltage transfer circuit and a ground terminal.
 10. Thedigital temperature sensing circuit according to claim 7, wherein thehigh voltage and the low voltage are included in the trimmed downdivided voltages.
 11. The digital temperature sensing circuit accordingto claim 1, wherein the code voltage generator comprises: a high-voltagetransfer circuit configured to apply the second reference voltage to anoutput terminal in response to the high voltage; a low-voltage transfercircuit configured to form a current path on an output terminal inresponse to the low voltage; and a second resistor string coupledbetween the output terminal of the high-voltage transfer circuit and theoutput terminal of the low-voltage transfer circuit and configured tooutput the divided voltages.
 12. The digital temperature sensing circuitaccording to claim 11, wherein the high-voltage transfer circuitcomprises: a fifth amplifier configured to compare the high voltage witha voltage of the output terminal of the high-voltage transfer circuitand then output a comparison result voltage; and a third switchconfigured to transfer the second reference voltage to the outputterminal of the high-voltage transfer circuit in response to thecomparison result voltage outputted from the fifth amplifier.
 13. Thedigital temperature sensing circuit according to claim 11, wherein thelow-voltage transfer circuit comprises: a sixth amplifier configured tocompare the low voltage with a voltage of the output terminal of thelow-voltage transfer circuit and then output a comparison resultvoltage; and a fourth switch configured to generate a current on theoutput terminal of the low-voltage transfer circuit in response to thecomparison result voltage outputted from the sixth amplifier.
 14. Thedigital temperature sensing circuit according to claim 11, wherein thesecond resistor string comprises a plurality of string resistors coupledbetween the output terminal of the high-voltage transfer circuit and theoutput terminal of the low-voltage transfer circuit.
 15. The digitaltemperature sensing circuit according to claim 14, wherein the dividedvoltages are outputted through nodes coupled between the stringresistors included in the second resistor string.
 16. The digitaltemperature sensing circuit according to claim 1, wherein the modeselector comprises: a multi-digital-to-analog converter supplied withthe temperature voltage and first sub-divided voltages included in thedivided voltages, and configured to output a positive voltage and anegative voltage in response to the mode select signal; a secondanalog-to-digital converter supplied with second sub-divided voltages,the temperature voltage, the positive voltage, and the negative voltage,and configured to output the first code for a first mode or anadditional code for a second mode in response to the mode select signal,wherein the second sub-divided voltages include voltages other than thefirst sub-divided voltages, among the divided voltages; and an adderconfigured to receive additional codes in set cycles in response to themode select signal, add the received additional codes, and output aresulting code as the second code for the second mode.
 17. The digitaltemperature sensing circuit according to claim 16, wherein a number ofbits of the second code is greater than a number of bits of the firstcode.
 18. A digital temperature sensing circuit, comprising: atemperature voltage generator configured to generate a temperaturevoltage varying with a temperature, a high voltage, and a low voltage; acode voltage generator configured to output divided voltages havingvarious voltage levels based on the high voltage and the low voltage;and a mode selector supplied with the temperature voltage and thedivided voltages, and configured to output first codes or second codeshaving a resolution higher than that of the first codes in response to amode select signal.
 19. The digital temperature sensing circuitaccording to claim 18, wherein the mode selector is configured to:output the first codes in response to a low-resolution mode signal, andoutput the second codes in response to a high-resolution mode signal.20. The digital temperature sensing circuit according to claim 19,wherein the second codes are outputted by adding codes generateddepending on the temperature for a time longer than that of the firstcodes.